Electric glow-lamp



(No Model.)

E. A. GOLBY. ELECTRIC GLOW LAMP.

No. 498,929. Patented June 6, 1893.

Maffay/m1711010' A l f1 W/ MESSA? A /NVEN'TOH l rma/LOL v4.

(L A v @Y VLWQMM'M @Nm3/ver..

UNITED STATES PATENT FEICE.

EDVARD A. COLBY, OF NEWARK, NEW JERSEY.

ELECTRIC GLOW-LAM P.

SPECIFICATION forming part of Letters Patent No. 498,929,0lated J' une 6, 1893.

Application led February l5, 1893. Serial No. 462,407. (No model.)

To a/ZZ whom t may concern:

Be it known that I, EDWARD A. CoLBY, of Newark, Essex county, New Jersey, have invented a new and useful Improvement in Electric Glow-Lamps, of which the following vis a specification.

My invention consists in an annular electric glow lamp containing a spiral filament in closed circuit. The said lament has no leading-in wires, and is rendered incandescent by being placed in a varying field, such as is produced in the vicinity of a conductor carrying a varying (alternating, pulsating or intermittent) current of electricity. In my present device the lamp is shown disposed in proximity to a coil through which the current passes, so that the spiral lilament becomes substantially the secondary of said coil.

My invention further consists in two coils arranged in said lamp, one of which is the filament. Said coils are connected in series, the free ends beingjoined to produce a closed circuit. The spiral filament is disposed outside of and surrounds the other coil, which may be of metal and which may also be embedded in the glass of the receiver.

In the accompanying drawings, Figure 1 represents the inner tube of my improved lamp with the carbon filament arranged thereon in the form of a continuous coil. Fig. 2 shows the lamp complete. Fig. 3 shows the lamp in place upon the core of an induction coil or transformer and thus arranged in operative position. Fig. t shows the arrangement of a coil in the lamp connected in series with the spiral filament.

Similar letters of reference indicate like parts.

The lamp which is shown in`Fig. 2, consists of an outer tube, A, and an inner tube, B, joined together at their ends in any suitable Way so as to produce a continuous glass vessel of annular form. The tube B, which, for convenience of construction, is separately made and which is shown in Fig. l, carries a wire, D, which is sealed at one end, E, into the glass of the tube.

F is a spiral filament of carbon of the kind usually employed in glow or incandescent lamps, having its extremities fastened to the supporting wire D. The filament F is rendered incandescent by placing the lamp in a varying field of force, such as is produced' around a conductor through which a varying (alternating, pulsating or intermittent) current passes.

In practice, and as here shown, I prefer to arrange the lamp so that the filament F is the secondary of a transformer or induction coil through the primary of which coil an alternating current of electricity is passed. A suitable construction for this purpose is represented in Fig. 3, in which G is the primary of an induction coil or transformer communicating with a suitable source of current by wires I J, and H the core thereof'. The core I-I, as is usual, is formed of a bundle of straight iron wires, and it is here shown as extending above the primary coil G. The diameter of the core Il is to be such that it will enter the tube B of .the lamp A, so that the lower portion of the lamp A rests upon the upper side of the coil G and is thereby supported.

The lamp A is exhausted by any of the known means used for producing vacuum in existing glow lamps.

When an alternating current of electricity is caused to traverse the primary coil G, the filament spiral F will, bythe current induced therein, be caused to glow; and of course the current in G is to be suitably regulated in point of strength and pressure to produce the desired degree of incandescence in the filament F.

In order to increase the potential dierence atthe terminal of the filament, I may employ a coil, K, of platinum wire. This coil closely surrounds the inner tube B of the lamp, and in fact may be embedded in the glass of said tube during the manufacture thereof. The ends of the spiral filamentF are connected to the ends of the coil K, so that the filament and coil are in closed circuit. The filament F also surrounds the coil K, as shown,so that filament and coil are thus connected in. series and unite to form a secondary coil to the primary coil G when the lamp is in place as represented in Fig. 3.

1. The combination in an electric glow lamp of an annular or hollow cylindrical rereo ceiver and a filament in the form of a closed spiral disposed concentrically with and inclosed in said receiver.

2. The combination in an electric glow lamp of an annular receiver, a support therein and a filament in the form of a closed spiral carried by said support and disposed concentrically with and inclosed in said receiver.

3. The combination in an electric glow lamp of an annular receiver, and inclosed therein two coils, one of said coils surrounding the other and connected in series and in closed circuit, substantially as described'.

4. The combination in an electric glow lamp of an annular receiver and inclosed therein a coil of platinum wire and a coil of filament surrounding said platinum wire coil,

the said coils being connected in series and in closed circuit, substantially as described.

5. The combination in an electric glow zo lamp having an annular glass receiver, a coil embedded in the inner tube B of said receiver and a spiral filament surrounding said coil, and connected thereto in series, the said coil and lament being in closed circuit.

6. The combination in an electric glow lamp having an annular glass receiver of a closed spiral filament and a support therefor within said receiver.

EDWARD A. COLBY.

Witnesses:

H. R. MoLLER, M. BoscH. 

